Memory reduction by Haar wavelet transform for MPEG decoder

In MPEG-2 HDTV (MP@HL) application, bandwidth and size of memory requirements are very large. These requirements increase the bus bandwidth and hardware cost. We present a simple method that requires low complexity hardware for MPEG-2 decoder memory reduction. Our algorithm is based on the Haar wavelet transformation and Haar basis with full-tree decomposition transformation. No additional multipliers are needed. Following the transformation, we use a variable-length coder to compress the data before storing them in the memory for future references. For memory accesses, we apply a group of macroblock segment coding and a hierarchical access method to reduce the access time. According to our simulation results, this technique can at least cut down the memory requirement from 12 Mbytes to 7 Mbytes for 4:2:0 HDTV real-time application. The real performance is dependent on the bit rate and the original MPEG2 decoded video quality.